US Fish & Wildlife Service
Date of this Version
1991
Abstract
Current Species Status: This species is listed as endangered. The number of individuals is unknown. However, it has undergone substantial range reduction in Kansas, Oklahoma, and Texas. It is extirpated in Kansas, and the Oklahoma population is below 300 birds. Declines have also been documented over much of the species’ range in Texas. Its status is uncertain in Coahuila, Mexico.
Habitat Requirements and Limiting Factors: The black-capped vireo occurs in mixed deciduous/evergreen shrubland. Breeding vireos use shrubby growth of irregular height and distribution with spaces between the small thickets and clumps and with vegetative cover extending to ground level. Habitat losses are occurring through development, over-browsing, and suppression and alteration of natural disturbance regimes. Cowbird nest parasitism has been drastically reducing vireo reproduction in many areas.
Recovery Objective: Downlisting
Recovery Criteria: All existing populations are to be protected and stabilized; and at least one viable breeding population (of at least 500 to 1,000 breeding pairs each) should exist in each of six regions, including one in Oklahoma, one in Mexico, and four in Texas; and sufficient and sustainable area should exist to support the birds when they are on their winter range; and all of the previously mentioned criteria should have been maintained for at least 5 consecutive years and assurance should exist that they will continue to be maintained. Threats from habitat loss, cowbird parasitism, and other factors will need to be resolved. Actions Needed: 1. Additional surveys.
2. Clarify population size, area requirements, and location needs for viable populations.
3. Maintain viable populations in target areas.
4. Conduct research On species’ biology, habitat needs and management, threats, and winter range.
5. Eliminate threats from cowbird nest parasitism, habitat deterioration, and other agents.
6. Develop and conduct a program for monitoring the vireo’s status.
Comments
U.S. Fish and Wildlife Service, Region 2.